Replace flash immermat timer with something decent! Help.

[Maths Grinds]

Hi there, we moved into a new house about two years ago, the house has an ideal logic system 18 gas boiler. This heats the rads and water at the same time (no separate control). Beside the boiler is a flash immermat timer which works (and a broken thermostat on the other side of the room which never worked and is not wired up, from the looks of things they gave up trying to get it to work). The mechanical flash immermat timer works fine with I think 5 wires attached to it Brown-Blue-Blue-Brown-Black but I can take a pic if anyone needs it.

So, I want to replace the mechanical timer with something more decent like a RF thermostat. The labor price to replace it is 80 euro!!! So would anyone recommend an easy replacement model? Ideally I would LOVE to take the immermat off the wall and stick on something that would fit the same hole and be not to hard to wire up with ideally an RF thermostat that I could stick on the wall.

Looking forward to any tips If I need to pay 80 to wire it up that's fine, just seems mad expensive to me!

 

[undertrained]

80 euros isn’t that bad IMHO

 

[Maths Grinds]

Thanks, any recommendations?

 

[undertrained]

Can you show us a pic of existing setup, then we know what may fit.

 

[Maths Grinds]

 

[undertrained]

Something like a programmable room thermostat. Honeywell T4? Drayton digistat?

 

[Maths Grinds]

Thanks, so for example with something like "Drayton RF601 Thermostat" be okay? My concern is (i) I don't want to drill holes when there is already something in place so would the SCR receiver be the same standard size as the timer already in place and (ii) how does one wire. I have 5 wires and there are 5 connections but the manual shows for 4 wires into the SCR and not the current 5 I have.

 

[undertrained]

If you want to replace a timer with a thermostat the new that may work, however if you want to use a timer and a thermostat, then a programmable room thermostat or a timer to replace your immermat and get the room stat functioning again. Wiring not 100% on. Maybe one of the other more experienced guys can help you? @ianmcd @stem?

 

[ianmcd]

Any modern RF stat will fit that setup as all now have a standard fixing plate that will go straight on to your existing pattress box, if you want to know the wiring however we will need to know what you are going to fit and what model that immermat is, I have only ever seen immermat immersion heater timers, didnt know the did CH timers everyday is a school day, can you post a pic of your HW Cyl it may have a mechanical control stat.

 

[Maths Grinds]

Hi there, yeah the immermat timer controls the central heating and at the same time the hotwater, both go on and off together. I have a standard electrical hot water tank (immersion) under the stairs that gets heated when the boiler goes on and the only control I have over it is a valve that determines how much hot water gets diverted to warming up the hot water tank. (And of course the manual bath sink switch with on and off). I can send a pic.

 

[Maths Grinds]

 

[undertrained]

That looks like a really dated system. No hot water temperature control, no zone valve(s), a broken stat, certainly no boiler interlock, not sure of foreign regs.

 

[Maths Grinds]

Sadly this is a new build home, building quality in Ireland is terrible.

 

[undertrained]

You’re telling me!

It might be best if you upgrade to provide independent heating and hot water, a cylinder thermostat (that could scale up rather quickly), a programmable room thermostat and maybe a 3 port mid position valve (y plan) or x2 2port valves (s plan). It would probably save you money in the long run.

 

[Maths Grinds]

Thanks but let's bear in mind I thought 80 euro was too much so I'm just trying to do what I can on my budget